I do 54t front and 12-25 11spd cassette. If it would be outside of that, I’d drop the front ring a tad.
You need a long straight downhill or ripping tailwind for 11 and 10t cogs. 100rpm in a 54 and 12 is 35mph.
Cmon. Just my stinky opinion.
And if you are spinning out your 53/12 on a downhill, it’s probably time to stop pedalling, tuck and enjoy the rest!
13-23 11speed straight block I would love this.
Also forgive me phone posting but someone mentioned a 8mm pitch chain system? Well Shimano did try 10mm.
https://progettopistavintage.blogspot.com/2013/05/shimano-dura-ace-10-mm-pitch-series.html
I.e., it’s pretty easy to soak up a lot of the jump simply by raising (or lowering) your cadence.
That’s not really an answer. It’s like saying that it’s easy to make up for slow tires by simply pedaling harder. Sure, it’s doable, but it’s what people are trying to avoid in the first place.
On my Emonda (Shimano 50-34 11-12-13-14-15-17-19-21-23-25-28), I occasionally plunge to the 34-11 as a solution to the 16-tooth cog problem. I don’t do it very often, but there are times when an effort is being held steady for a bit and both the 50-15 and 50-17 are less comfortable. Splits those gears nicely.
I have something similar going on on my TT bike. In races, I use mostly the 52x19, 52x17 and 52x15. The jump from the 19 to the 17 cog is no biggy but for some reason the jump from 17 to 15 feels quite heavy. Feels like I’m grinding too much even though I’m still spinning at 90-95 rpm cadence, so I end up shifting back into the 17 cog spinning at 105rpm… A 14-28 cassette seems perfect here. However when you start to think of 1X, on a hillier course or a flat course with the occasional short but steep climb, a 36x23 can be handy too… So that would require a 32 or 34 cog for the 52t chain ring, meaning I would have to mix match a 14-28 and an 11-32 cassette or something similar…
As with all wind tunnel testing the more data you have, the more data you wish you had!!
My data on VumaChrono shows 4-6 watts advantage to the domed aero design depending on yaw angle and direction compared to the DA crank of the era: 2008/2009 when development was happening. Removing FD and inner ring could be another 2-4 at low yaw and doesn’t seem to matter at higher yaw. 53 vs 55 was undetectable in what I have.
What I don’t have is anything on derailleur cage length, cassette size, oversized pulleys, etc… I do have one data point on the early Berner oversize cage with the wing shaped cage design. This looks to be ~10-15 grams of drag better than a standard SRAM Red cage of 2010, and I speak in grams of drag as 9grams is considered the floor of repeatability of that tunnel… so it appears to be significant enough to call it an improvement, but just barely.
With this cage being about 30% longer but more aero in form than a standard cage netting you ~1-1.5 watt aero savings I would imagine that making the un-aero cage form 30% larger is probably costing you a similar amount, but hard to say without testing it.
Thanks for the input, Josh. Your data seems to pass the smell test and jives with what little I’ve seen or heard in this regard.
I assume your numbers are all without a rider on board and I’d wager that the differences are unlikely to increase with a rider on board (and probably rather decrease, at least for the stuff downstream like RD, cassette, and cage). I remember Steve Hed mentioning results changed when testing disc wheels with vs. without a cassette, but the aero hit of a cassette is likely quite a bit smaller in a bike with a rider on vs. a stand-alone wheel (the cassette seems to be fairly sheltered in many frames).
Sounds like oversized pulleys might be close to a wash, depending on speed, yaw, power output, chain, and whatnot. I’ve thought about testing it for some time, but the truth is it would be rather time-consuming trying to work out what might be 1-2W faster or slower everything considered so something more important always takes precedent. That Berner cage is pretty nice - but probably quite a hassle to keep the pulleys clean!
As a UK TTer the need for a ‘big’ gear is for tailwinds. Particularly in a longer event when you could have a tailwind for 25 miles. You could be averaging over 30mph for that and you don’t necessarily want to be at 110rpm for that 50min.
Nobody is debating the need for big gears but rather can we really justify small cogs when they have such friction penalties…especially when we are doing so much other complex and expensive stuff to offset similar frictional and aero challenges. For UK TT’s, and with the ProTour teams we work with, we advocate for big chainrings as well as rear clusters that put the bulk of the use at the straightest possible chainline on the largest possible cogs for running efficiency.
I.e., it’s pretty easy to soak up a lot of the jump simply by raising (or lowering) your cadence.
That’s not really an answer. It’s like saying that it’s easy to make up for slow tires by simply pedaling harder. Sure, it’s doable, but it’s what people are trying to avoid in the first place.
I agree with you here. Rapp completely lost me with this argument. I mean, we can “make up” for all us this stuff somehow…increase cadence, better lube, etc. But, increasing your cadence comes at a price–increased effort. I think the point is to figure out the fastest set up–to the extent that is possible–when equalizing these things.
Increasing your cadence with a smaller gear ratio shouldn’t meaningfully increase “effort.”
For example, 50x16 is a ratio of 3.125.
48x16 is a ratio of 3.0.
To go the same speed in 48x16 as in 50x16 at 90rpm requires you to pedal the 48T at 94rpm. But there should be NO power differential between the two. And, based on what we know about pedaling, people are generally equally efficient at 90 & 94 rpm.
Within a band of about 5-10rpm (total variance) - at the same power output - people are unlikely to perceive much difference.
If you have a marginally lighter (or heavier) gear, you pedal marginally faster or slower. That does NOT mean you put out more power.
I can easily discern the difference of 4—and certainly 10—rpm and I’m not a high level cyclist. Regardless, it does, in fact, require more effort. We can also argue that no one notices the difference in friction, or a few watts from the removal of FD, but those differences exist and I believe the point of the discussion is to find the tipping point for all of this.
But you know you want some big ring goodness…it brings up more fun conversations about how big you are, and if you can use all of it.
Just today, did some downhill 4km pursuit intervals averaging 30mph including the start from dead stop. Going certainly over 30mph for about 4 1/2 minutes. I do those downhill because I’m too slow for a 4km pursuit interval to be flat/uphill…it would take me too long, lol.
So yes, it is big, and yes…I can use all of it.
Increasing your cadence with a smaller gear ratio shouldn’t meaningfully increase “effort.”
And, based on what we know about pedaling, people are generally equally efficient at 90 & 94 rpm.
“Equally efficient” is an extreme oversimplification of a complex relationship. They’re certainly not identical in terms of what loads they put on the body’s systems.
Personal thoughts: I reckon it’s time we reevaluated 1/2" chain as the standard. Go to say 10mm pitch and you could increase tooth count, decrease articulation, increase contact points (lower stress per tooth=less friction), AND have small frontal area…
Yes! I posted the very same thing recently, and have been suggesting it for about a decade. A 13t cog would be nearly as small as a 10t.
Low tooth counts suck. Not just 10, but 11 and 12 also. Too much chordal variation.
I once used a 28 and have never owned anything larger than a 25, I’d probably choose knee surgery over a giant rear cluster (and am likely on that path already!) and have often muttered things like 'If Andy Hampsten could climb the Stelvio"… you get the idea)
…or Eddy… climb something. Love this montage, and the music. Slo-mo steep mountain grinding at 4:00.
Increasing your cadence with a smaller gear ratio shouldn’t meaningfully increase “effort.”
And, based on what we know about pedaling, people are generally equally efficient at 90 & 94 rpm.
“Equally efficient” is an extreme oversimplification of a complex relationship. They’re certainly not identical in terms of what loads they put on the body’s systems.
My issue is that people perceive that with a 2X system, riders are always able to find their exact “optimal” setup and that somehow that is not possible with a 1X system.
A 2x12 system is still discrete in terms of gearing. It may be easier to come closer to your “preferred” cadence, but we’re not talking about a CVT drivetrain here where you just dial in your exact cadence and adjust the ratio so that your power is exactly what you want. And, as is easily seen mathematically, a 2x system never has twice as many distinct & usable ratios as a 1x system does.
I’m not saying that someone wouldn’t notice a 4rpm - or even 10rpm - difference. But the idea that you are always in the “right” gearing with a 2x system and necessarily in the “wrong” gearing with a 1x system is my contention. For a given rider, 50x15 might be the ratio that they use most often and is most suited to their strengths/preferences. With a 53/39 2x drivetrain, they’d then be overgeared with 53x15 or undergeared with 53x16. So, in that case, the “extra” 4 beats of cadence might actually be a good thing.
The idea that a 1x drivetrain necessarily puts you in a ratio than a 2x drivetrain and therefore that is also always necessitates more “effort” is irrational.
Nobody is debating the need for big gears but rather can we really justify small cogs when they have such friction penalties…
Do you have data to quantify the penalty of going from 11T to 10T or 9T (I have yet to listen to the latest podcast Mr. Rapp referenced in the OP & think you were spit-balling with the “… 10t cog is costing you 6 watts of additional friction …” comment in post 16)?
Based on Jason Smith’s work at Ceramic Speed, it appears there’s about a 0.6 watt difference going from a 12T to an 11T cog. Some significant (but unknown) % of that loss is due to the change in chain line, as the loss was measured moving down a cog on the cassette. So, how bad could going from 11T to 10T be? another 1 watt? 1.5 watts? What about a 9T cog? another 3-5 watts (I’m assuming the penalty gets incrementally worse relative to nominal change in gain ratio)?
For the small fraction of total ride time one would actually use a 10T or 9T cog, that’s not a bad penalty for the flexibility of having a 1x setup that will allow a higher gain ratio (i.e. enable the use of a smaller chainring up front). Especially when you get to remove this:
And when using that 10T or 9T cog, as you noted, velocity is damn fast, where FA makes that much more of a difference.
Even with everything else held constant many more variables remain (e.g. % of time spent in big vs small rings in a 2x setup vs. relative size of 1x ring, relative chainline vs the offset nature of 1x rings, relative cassette sizing, the use of a clutched derailleur for 1x, etc.), but net-net, I think Mr. Rapp is coming out even (or maybe even ahead) in the watts department. And he doesn’t have to deal with shifting a second chainring, which, as Stan has previously pointed out, can be confusing.
My issue is that people perceive that with a 2X system, riders are always able to find their exact “optimal” setup and that somehow that is not possible with a 1X system.
I don’t think that’s what anyone actually perceives; it seems like you’re making a pedantic reading of IT’s original post. The point is that you’re on average able to stay closer to what your body wants with a 2x system than a 1x.
The size of the cassette’s straight block is a relevant issue, because the 15-17 jump of ~13% is around where a lot of folks start getting really annoyed by the gap. A typical Shimano 50-34 11-28 has only one gap in the cassette that’s this big, and a double-shift can circumvent it. By contrast, if you want similar range out of a 1x system, you’re going to need a cassette around 11-40 or bigger, and the average step size on such a cassette is bigger than this common annoyance threshold.
Obviously all considerations are subject to the particular use case. On a low-wind pancake, most people would be plenty happy on a 1x drivetrain with a 50T chainring and a 12-25 cassette.
And, as is easily seen mathematically, a 2x system never has twice as many distinct & usable ratios as a 1x system does.
That’s usually true in practice, but mathematically speaking, it doesn’t have to be the case.
One of my bikes is a counterexample: it’s a 1980s 2x6, 52-42 crankset with 14-16-18-21-24-28 freewheel. The chainrings 1.5-step the freewheel reasonably well; the two jumps at the extreme ends of the range are unavoidably big, but everywhere else you can easily find intermediate gears.
I actually really wish that Shimano would launch a half-step synchro arrangement. It would be entirely possible for a 2x11 to have a ~500% gearing range with jumps mostly at 10% and below. And with synchro, the constant small front shifts wouldn’t be very noticeable.
Now that makes more sense is is something with which I completely agree. As an AGer, I always ask, what are the consequences to me if I’m in a slightly less than optimal gear…? The answer is what you now suggested—pedal a little faster or a little slower. That’s it. If I go .1 MPH less, my life goes on. Heck, I switched to 1x partially because I felt like I was finding myself in that awkward in between getting far too often with 2x (and somewhat motivated by your encouragement to try it years ago),
I can easily discern the difference of 4—and certainly 10—rpm and I’m not a high level cyclist. Regardless, it does, in fact, require more effort. We can also argue that no one notices the difference in friction, or a few watts from the removal of FD, but those differences exist and I believe the point of the discussion is to find the tipping point for all of this.
IMO downplaying the impact to the rider (the engine with a mind) is a mistake. Yes, all the little things without a mind of there own add up. Yet, the mind of the rider is making decisions based on how the engine feels.
What is the tipping point?
When 1X systems have a two tooth jump throughout the rear cassette, a jump of two is too much for me not to be impacted. If the rider is in that awkward place where the gear doesn’t seem right, the natural inclination is to go back and forth which is a significant loss of power too. Now a 1X system with just a one tooth increase across the cassette until the last bigger three, that I could see.
Oooooh… this is getting so good!!
I need to point out that people are conflating my anti-10t cog stance as being anti 1x… it’s not. I love 1x and as mentioned previously was involved in the birth of it… my contention is that we are doing it wrong, or at least doing it sub optimally.
Jordan’s point that a 2x drivetrain doesn’t have 2x as many usable ratios as a 1x is also spot on… many of them overlap or nearly overlap, though this assumes similarly large ranges of cassette.
I love the graphic presented by davews09… it certainly highlighted for me that modern, electronic FD’s probably have at least 2x the FA of the mechanical derailleurs we were looking at back in 2008-2009, so the advantage of losing the FD is probably greater than the 2-4 watts we measured at that time.
For the benefit of davews09, the 6 watts comes from a recent Velonews article showing a 6 watt advantage in testing to a 53-11 compared to a 48-10. In the original reading and ST thread related to the article, the headline was ‘1x sucks’ which I defended 1x in and pointed out that it isn’t the fault of 1x but rather the use of these small cogs… each tooth lost in the rear cog has a disproportionately larger effect on friction than the previous one…
So the original statement made on the Marginal Gains podcast was that the 10t cog was a bad idea and that if you need a gear like that you should be going up on chainring so you can use larger cogs in the rear… and I may have called the 10t stupid, and I’ve been known to refer to it as a ‘vanity gear’ in the past… which is somewhat provocative on a number of angles, but my big point was that people will spend $1000 for ceramic bearings to save 1 watt or $750 for oversized pulley wheels to save 1-2 watts and then use a 48-10 when a 50-11 would be at least a watt or two faster and a 53-12 would be a watt faster still and that’s assuming you use it… which most don’t. I tell my ProTour teams that the ONLY point to the 11t cog in a TT is to give you better chainline to the 12t cog… so much better to go 56t front and spend 90% of your time in the 13-14-15 with the occasional 12 or if something crazy happens, you have the 11, but honestly it rarely gets used.
In my opinion the problem with how we’ve tried to do 1x is that we’ve tried to match the range of something like a 53/39 with 11-34 to prove the point that the 1x can match the range of this super wide 2x… which I would argue is way wider than most anybody actually needs also…
At the end of the day, riders should spend the money saved on the FD and buy a couple of cassettes that provide more specificity for the situation at hand. Or at least think of moving to a 50x11 setup as being at least the equivalent of a ceramic bearing upgrade over a 48-10 setup.
